The present invention relates to a device for coating granular solids such as tablets, catalyst carrying particles or the like.
There has been divised and demonstrated a rotary drum coating device of the type wherein the drum shell is formed with a large number of small holes for permitting the charging of gas into or discharging of gas from the rotary drum. In the device, such as that mentioned above, in order to discharge the coated granular solids, the drum shell is provided with a discharge damper operable by an air cylinder or the like. Alternatively, the rotary drum is inclined to discharge the coated granular solids. As a result, the coating device is very complex in construction, the maintenance is difficult, and the discharge of the products require a large number of labors and a long time. In order to solve this problem, there has been devised and demonstrated a coating device of the type wherein a discharge opening is formed through one of the side walls of the rotary drum, but the discharge still requires a long time.
In the coating devices of the types described, a coating material spraying nozzle and a blowing duct are extended through openings formed through one of the side walls of the rotary drum so that the maintenance thereof is still difficult.